GHSA-h4fr-cmh5-qr62 - Fallow: A `.*` glob segment let an analyzed repository make Fallow test paths in the parent of the project root
### Impact
Fallow expands some globs from the analyzed repository on disk. Before 3.34.0, a segment such as `.*`, `.?` or `..*` in such a glob also matched the special `..` entry. The `glob` crate tests `..` against a segment that starts with a literal `.`. Fallow validates plugin glob patterns and refuses absolute paths and `..` segments, but these segments passed that validation.
The attacker controls the repository content. The attacker must also be able to read the Fallow output, for example a CI log or a pull request comment. Then the attacker can learn if a file or directory exists in the parent of the project root:
- A plugin `fileExists` detection pattern such as `.*/marker.json` made the plugin active when `marker.json` existed in the parent directory.
- An external plugin `configPatterns` or `alwaysUsed` pattern could match a config file in the parent directory. When the plugin was active and declared `toolingDependencies`, the tooling detection credited the related dev dependency. An unused dependency finding could then disappear, and `--trace-dependency` printed the outside path.
- `fallow plugin-check` reported `path_exists: true` for a seeded entry that matched only in the parent directory.
Fallow tested only that these paths exist. It did not read or print the content of a file outside the project root through these globs.
The Jest, Vitest and Rstest project globs had the same `.*` problem, and the Jest and Vitest ones also read file content. GHSA-jfwm-3p3c-6hx5 describes that case.
### Patches
Fixed in 3.34.0. Fallow now rewrites a leading `.` in a wildcard segment to `[.]` before it expands the glob on disk. `[.]` matches the same hidden files and directories inside the project root. The `glob` crate does not test `..` against it.
### Workarounds
Run Fallow only on repositories that you trust. Before you run Fallow on another repository, check the `detection`, `configPatterns` and `alwaysUsed` patterns of its plugin files.
LOW
Severity & confidence
Source severitylow
Platform severitylow
Confidencemedium
Exploitationunknown
CVSS3.3
Affected
Vendorsfallow@fallow-clifallow-clifallow-configfallow-core
Productsfallow@fallow-cli/fallow-nodefallow-clifallow-configfallow-core
Reporting sources (1)
GitHub Security Advisories
Timeline & provenance
Published2026-10-23T21:58:16
Last updated2026-10-27T18:57:27
Ingested2026-10-23T22:03:29
FreshnessNEAR-REAL-TIME
Threat typeadvisory
Recommended action
Review the advisory and upgrade affected packages to the first patched version.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a single or secondary source; treat as indicative, verify before acting.
Source type: vendor ยท Original: GitHub Security Advisories